Final answer:
The recommended tube colors in cathode ray tubes of RGB displays correspond to red, green, and blue light with specific wavelengths. The frequency and energy of a photon for each of these colors can be calculated using the speed of light, Planck's constant, and the respective wavelength.
Step-by-step explanation:
The recommended tube color refers to the colors produced by cathode ray tubes in RGB color television and computer displays. These tubes mix red, green, and blue light to create the spectrum of visible colors. The wavelength for red light is approximately 620-750 nm, for green it is around 495-570 nm, and for blue, it is about 450-495 nm. The frequency (ν) and energy (E) of a photon can be calculated using the formulas ν = c / λ and E = hν, where c is the speed of light (3 x 108 m/s) and h is Planck's constant (6.626 x 10-34 J s).
To find the frequency and energy for each color, you could use these equations with the appropriate wavelength values for red, green, and blue light. The frequency will be higher for blue and lower for red, with green in the middle, because frequency is inversely proportional to wavelength. Correspondingly, the energy of a photon will be highest for blue light and lowest for red, as energy is directly proportional to frequency.